1. Field of the Invention
The invention relates to an electrical terminal with a housing, with a terminal chamber formed in it, and two conductor inlets which lead into the terminal chamber for the electrical conductors to be connected, with one conductor connection arrangement located in the terminal chamber for each conductor inlet, each conductor connection arrangement being formed of a current bar and a clamping leg of a clamping spring, the clamping leg and the current bar forming a spring force clamping terminal for an electrical conductor to be connected, and the two clamping legs each being connected to a contact leg.
2. Description of Related Art
Electrical terminals are used for electrical connection of at least one electrical conductor to a device, especially to a circuit board located in a device. These terminals are often also called printed terminals. In this connection, different electrical terminals are distinguished especially by the different connection possibilities for the conductors to be connected. Thus, terminals with screw, spring force, and insulation piercing clamping terminals as the conductor connecting arrangement are known.
Spring force terminals have become established on the market over time in addition to screw terminals, and for some time also in addition to electrical terminals with insulation piercing connection technology, and are being used in the millions, both as printed terminals and terminal blocks. The advantage of spring force terminals as compared to screw terminals is that the spring force terminals enable more rapid and simpler wiring. In this connection, two different types of spring force terminals are used; loop-shaped tension spring terminals and somewhat U-shaped or V-shaped open clamping springs which are also called leg springs.
To actuate a loop-shaped tension spring terminal, an actuating tool is needed, for example, a screwdriver, which is pressed into the actuating shaft to open the tension spring. In doing so, the tip of the screwdriver tensions the tension spring, by which the clamping site opens. A conductor to be connected can be inserted through a recess into the clamping leg, and after pulling out the screwdriver, is clamped against the contact leg of the tension spring or a current bar which is connected to the tension spring by the lower edge of the recess (compare, Phoenix Contact, product catalog “CLIPLINE 2005, page 19, German Patent Application DE 197 11 051 A1 or German Patent DE 101 53 170 C1).
U-shaped or V-shaped open clamping springs have one clamping leg and one contact or holding leg, the conductor which is to be connected and which is generally a rigid conductor or a conductor with a wire end ferrule, can be inserted into the terminal without a tool. By inserting the conductor, the clamping spring is automatically opened and then the inserted, stripped conductor is pressed by the clamping leg against a current bar. Due to this manner of actuation, these open clamping springs are also designated an edge socket connection or compression spring (compare, Phoenix Contact, product catalog “CLIPLINE 2005, page 20, German Patent DE 102 39 273 A1 and corresponding U.S. Pat. No. 6,814,608 B2).
For electrical connection of the electrical terminal to at least one printed conductor of a circuit board, the contact elements located in the known terminals have at least one solder pin which is inserted into a hole provided in the circuit board and then soldered in it. To do this, generally, the hole is filled beforehand with a solder paste, and then, the solder pin is electrically connected to the corresponding printed conductor by means of reflow soldering.
German Patent DE 198 38 008 B 4 discloses a spring force terminal for use on circuit boards, which has a quick-connect terminal located in the housing, from the wall of which terminal at least one elastic clamping leg is punched, with a clamp end which, together with the opposing wall of the quick-connect terminal, forms a spring force clamping terminal for an electrical conductor to be connected. In the known terminal, two clamping legs located next to one another are punched out of the quick-connect terminal so that the terminal can be used for connecting two conductors which can be inserted into the housing parallel to one another. On the side of the housing opposite the conductor insertion openings, in the known terminal two solder pins connected integrally to the quick-connect terminal emerge and are used for electrical connection of the terminal to the printed conductors of a circuit board.
German Patent DE 42 10 020 C2 discloses the initially described electrical terminal which is likewise made for connecting two conductors. In this electrical terminal, the two conductor inlets are located on two different connection sides of the housing which run at an angle of 90° to one another. On the third side of the overall roughly square housing there is another conductor connection arrangement which can be made as a push-lock terminal or a printed solder connection. Within the housing, there is a roughly W-shaped clamping spring which has two clamping legs which, with a respective adjacent electrically conductive contact wall, each forms a spring force clamping terminal for a respective electrical conductor to be connected. Due to the execution of the W-shaped clamping spring and the arrangement of the conductor inlets on different sides of the housing, the known electrical terminal has a relatively large construction. Moreover, the two electrical conductors to be connected can only be inserted into the electrical terminal at the same time relatively awkwardly and can only be pulled out of the terminal in succession.
Due to the general reduction in the dimensions of the electronic devices used at present and especially also circuit boards, terminals with smaller and smaller dimensions are also desirable. In this connection, various proposals have already be advanced for reducing the dimensions of the electrical terminals and for making available as large a number of connection possibilities as possible at dimensions which are as small as possible. In this connection, so-called two-tier terminals or three-tier terminals which both as screw terminals and also tension spring terminals are noted as belonging to the prior art.